scholarly journals Analysis of a Continuously Variable Transmission in which Four-Bar Linkages Are Arranged in Parallel

2019 ◽  
Vol 9 (2) ◽  
pp. 20 ◽  
Author(s):  
Toshihiro Yukawa ◽  
Syoma Kumagai ◽  
Taiyo Fujisawa ◽  
Yoshiaki Oshida ◽  
Youichi Takeda ◽  
...  
Keyword(s):  
Power Consumption ◽  
Real Time ◽  
High Precision ◽  
Structural Type ◽  
Continuously Variable Transmission ◽  
Continuous Control ◽  
Precision Control ◽  
Input Shaft ◽  
Variable Transmission ◽  
Linear Actuators

This paper describes a development of a new structural type of continuously variable transmission (CVT). We here propose a CVT with linkages and irreversible mechanisms which does not positively depend upon frictional conduction force between conduction components. In the proposed CVT, four lever-crank units are connected in parallel mechanically with the cranks at an input shaft, and the output shaft is also connected mechanically via an irreversible mechanism installed at the fulcrum of the lever. In the experiment, we confirm that the continuous control of gear ratios in real time by realizing high-precision control for expansion and contraction of the links using electric linear actuators. As a merit of the developed linkage type of CVT, it reduces power consumption, compared to other conventional CVTs.

scholarly journals Real-Time Control Strategy for CVT-Based Hybrid Electric Vehicles Considering Drivability Constraints

2019 ◽  
Vol 9 (10) ◽  
pp. 2074 ◽  
Author(s):  
Hangyang Li ◽  
Yunshan Zhou ◽  
Huanjian Xiong ◽  
Bing Fu ◽  
Zhiliang Huang
Keyword(s):  
Real Time ◽  
Fuel Consumption ◽  
Electric Vehicles ◽  
Hybrid Electric Vehicles ◽  
Continuously Variable Transmission ◽  
Speed Ratio ◽  
Driving Pattern ◽  
Variable Transmission ◽  
Equivalent Factor ◽  
Hybrid Electric

The energy management strategy has a great influence on the fuel economy of hybrid electric vehicles, and the equivalent consumption minimization strategy (ECMS) has proved to be a useful tool for the real-time optimal control of Hybrid Electric Vehicles (HEVs). However, the adaptation of the equivalent factor poses a major challenge in order to obtain optimal fuel consumption as well as robustness to varying driving cycles. In this paper, an adaptive-ECMS based on driving pattern recognition (DPR) is established for hybrid electric vehicles with continuously variable transmission. The learning vector quantization (LVQ) neural network model was adopted for the on-line DPR algorithm. The influence of the battery state of charge (SOC) on the optimal equivalent factor was studied under different driving patterns. On this basis, a method of adaptation of the equivalent factor was proposed by considering the type of driving pattern and the battery SOC. Besides that, in order to enhance drivability, penalty terms were introduced to constrain frequent engine on/off events and large variations of the continuously variable transmission (CVT) speed ratio. Simulation results showed that the proposed method efficiently improved the equivalent fuel consumption with charge-sustaining operations and also took into account driving comfort.

Optimization of Hydraulic Pressure for Continuously Variable Transmission

2011 ◽  
Vol 317-319 ◽  
pp. 529-532
Author(s):  
Kei Lin Kuo
Keyword(s):  
Torque Converter ◽  
Transmission Efficiency ◽  
Gear Ratio ◽  
Continuously Variable Transmission ◽  
Hydraulic Pressure ◽  
Primary Input ◽  
Input Shaft ◽  
Variable Transmission ◽  
Labview Program ◽  
Set Up

Compared to conventional transmission layouts, Active continuously variable transmission (CVT) provides smoother gear shifting and gear ratio in smaller increments, and is, therefore, more accommodating the needs of both the driver and passengers. A few notable improvements are enhanced passenger comfort, higher transmission efficiency, and improved acceleration. Incorporating all of the above qualities has become a major developmental focus for the automotive industry, and the potential for improvement warrants further investigation. A CVT controls the gear ratio by changing the diameters of the primary (input) and the secondary (output) pulleys by adjusting the hydraulic pressure applied to each using valves. Hydraulic pressure in the channel is developed using a basic pump connected to the input shaft. Excess pressure produced at higher speed is wasted. This study aims to minimize this hydraulic pressure without affecting the transmission’s performance, in order to conserve energy. A user interface was set up and the CVT’s torque converter was modified such that the inner and outer shafts could be operated independently, allowing for full control of hydraulic pressure .This experiment successfully achieved, via a custom LabVIEW program, its goal of controlling the gear ratio between the primary and secondary pulleys whilst operating at lower pressures to those specified by the manufacturer. This proves that it is possible to fully control the CVT whilst operating at a reduced hydraulic pressure.

High-precision control of linear actuators incorporating acceleration sensing

2000 ◽  
Vol 16 (5) ◽  
pp. 295-305 ◽  
Author(s):  
Kok Kiong Tan ◽  
Ser Yong Lim ◽  
Tong Heng Lee ◽  
Huifang Dou
Keyword(s):  
High Precision ◽  
Precision Control ◽  
Linear Actuators

Development of the Sphere-Toroidal Continuously Variable Transmission

2014 ◽  
Vol 986-987 ◽  
pp. 1315-1318
Author(s):  
Shun Min Wang ◽  
Zhuo Li ◽  
Xin Yu Wang ◽  
Xi Chao Li
Keyword(s):  
Continuously Variable Transmission ◽  
Traction Drive ◽  
Input Shaft ◽  
Variable Transmission ◽  
Working Principle ◽  
The Cross ◽  
The Difference ◽  
Toroidal Traction

This paper describes a new genre of Toroidal-CVT system, called the Sphere-Toroidal Continuously Variable Transmission (STCVT), which is derived from the half-toroidal traction drive (TCVT) and introduces its structure and working principle. The torque transfers from the input shaft to the cross-axle universal shaft coupling connected with the driven shaft. By discussing the difference between the torque-transfer, the paper will show the possibility of the application in the vehicle. To conclude, the system has the potential to implement infinite extension for the CVT theoretically.

Analysis of a New Form of Intrinsically Automatic Continuously Variable Transmission

2010 ◽  
Author(s):  
Timothy Cyders ◽  
Robert L. Williams
Keyword(s):  
Power Transmission ◽  
Mechanical Design ◽  
Peak Torque ◽  
Continuously Variable Transmission ◽  
Speed Ratio ◽  
Input Shaft ◽  
Positive Displacement ◽  
Variable Transmission ◽  
System Output ◽  
Human Powered

Effective continuously variable transmission (CVT) designs have been sought after for many years as their integration into many different mechanical systems can give many advantages over a discrete transmission system. Currently, CVTs are becoming popular for applications from automotive power transmission to wind power generation. Most CVT technologies, however, are friction- or hydraulic-based designs limited by both performance and system characteristics. This paper will evaluate a new, patented form of purely mechanical, intrinsically automatic CVT which is not based on belts, pulleys, gears or hydraulics. This new transmission is based on a deformable four-bar design incorporating a one-way clutch for positive displacement of the output. As torque demand on the system output is varied, the output’s displacement varies inversely to maintain a constant peak torque on the input shaft. The end result of this behavior is a possible instantaneous variation of speed ratio over an extreme range with a lightweight, simple mechanical design. This paper provides an analysis of the mechanism and its performance, as well as simulation results incorporating real-world measurement of system output into several different mechanical applications: a human-powered vehicle, an automobile and a centrifugal pump.

scholarly journals Dynamic Adaptive Low Power Adjustment Scheme for Single-Frequency GNSS/MEMS-IMU/Odometer Integrated Navigation in the Complex Urban Environment

2021 ◽  
Vol 13 (16) ◽  
pp. 3236
Author(s):  
Peihui Yan ◽  
Jinguang Jiang ◽  
Yanan Tang ◽  
Fangning Zhang ◽  
Dongpeng Xie ◽  
...  
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Real Time ◽  
High Precision ◽  
Single Frequency ◽  
Low Power Consumption ◽  
Integrated Navigation ◽  
Precision Positioning ◽  
Average Power Consumption ◽  
Mems Imu

Positioning accuracy and power consumption are essential performance indicators of integrated navigation and positioning chips. This paper proposes a single-frequency GNSS/MEMS-IMU/odometer real-time high-precision integrated navigation algorithm with dynamic power adaptive adjustment capability in complex environments. It is implemented in a multi-sensor fusion navigation SiP (system in package) chip. The simplified INS algorithm and the simplified Kalman filter algorithm are adopted to reduce the computation load, and the strategy of adaptively adjusting the data rate and selecting the observation information for measurement update in different scenes and motion modes is combined to realize high-precision positioning and low power consumption in complex scenes. The performance of the algorithm is verified by real-time vehicle experiments in a variety of complex urban environments. The results show that the RMS statistical value of the overall positioning error in the entire road section is 0.312 m, and the overall average power consumption is 141 mW, which meets the requirements of real-time integrated navigation for high-precision positioning and low power consumption. It supports single-frequency GNSS/MEMS-IMU/odometer integrated navigation SiP chip in real-time, high-precision, low-power, and small-volume applications.

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